In devices such as high temperature turbomachines there is a very large temperature rise in going from the ambient temperature at which the device was assembled to its operating temperature. This temperature rise which can be 1000 .degree.F., or more, causes thermal expansion of the components and presents centering problems in maintaining seals as well as the operating relationships between the various parts. In the case of a high temperature power recovery expander, for example, three different sets of expensive pin rings are employed to control radial expansion due to thermal growth and to maintain centering of the inlet casing, first stage stator and second stage stator.